1. Field of Invention
This invention relates to tire building equipment. More particularly, this invention relates to an anti-flex assembly for axial stability in tire manufacturing equipment, specifically, tire manufacturing equipment which includes a rotatable, expandable and collapsible drum.
2. Description of the Related Art
Tire manufacturing processes, including the manufacture of motor vehicle tires, typically includes fabrication of a cylindrical carcass as a precursor product to the completed tire. A tire carcass is formed by laying down various components of the tire onto the outer circumference of a rotatable, expandable and collapsible drum. The drum must rotate to facilitate uniform tire carcass construction. The drum must expand to facilitate construction of the desired size tire carcass. The drum must contract to facilitate removal of the tire carcass from the drum.
Adjustability of the diameter of tire building drums commonly involves a plurality of segments which are moveable between radially collapsed positions and radially expanded positions in which the segments collectively define the outer circumference of the drum. U.S. Pat. No. 6,390,166 (“the '166 patent”), which patent is incorporated herein in its entirety by reference, discloses a tire building drum of this type. The device of the '166 patent includes generally a plurality of segments collectively defining the outer circumferential surface of a generally cylindrical drum. The segments are mounted by way of a system of linkages about a central main shaft which allows the segments to be selectively repositionable between expanded positions radially of the rotational axis of the drum and collapsed positions radially of the drum in which a portion of the segments are brought into overlying relationship with other of the segments to collapse the diameter of the drum. Positioning the segments in the expanded positions provides a relatively continuous circumferential outer surface of the drum, thereby permitting layup of various components of a tire carcass thereon for forming of the tire carcass. Positioning the segments in the collapsed positions collapses the diameter and circumference of the drum to permit the removal of a formed tire carcass from the drum.
Additionally, the plurality of segments are divided into two sets, one set being disposed on each of the opposite sides of a transverse centerplane of the drum, the centerplane being oriented normal to the rotational axis of the drum. The two sets of segments are mounted for selective positioning thereof axially of the drum from a location external of the drum to adjust the overall working width of the drum. The axial and radial movements of the divided sets of segments are accomplished by unique mechanisms which provide for both selective and coordinated movements of the segments from locations external of the drum. These mechanisms include a series of alignment rods which serve to provide axial stability to the two sets of segments as the width of the drum is adjusted. Unintended axial movement of the drum can cause nonuniform tire carcass development, thus a need in the art exists for innovative systems to increase axial stability of the drum manufacturing equipment.